Coal-dust feeder.



J. W. ZELL.

GOAL DUST FEEDER. APPLICATION FILED NOV. 23, 1909. RENEWED JAN.5, 1911.

Patented M51117, 1911.

3 SHEETS-SHEET 1v J. W. ZELL. GOAL mm FEEDER.

APPLICATION FILED NOV. 23, 1909. RENEWED JAN. 5, 1911. 259 Patented Mar.7, 1911.

3 SHEETS-SHEET 2.

H P Elwuwwtoz J. W. ZELL. GOAL DUST FEEDER.

APPLICATION FILED NOV. 23, 1909. RENEWED JAN. 5, 1911.

986,259 Patented Mar. 7, 1911.

3 SHEETS-SHEET 3.

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'TlE1 3 GEM/M4 6 aonn w. znLL, or nunoamvou, rnnnsgrnvama, nssnssronor own-HALE PENNELL, or Dunc-Amman, rnnnsrnvama.

Specification of Letters latent.

COAL-DUST FEEDER.

Patented Mar- 7, 1911.

Application filed November 23, 1909, Serial No. 529,636. Renewed January 5, 1911. Serial H0. 600%.

To all whom it may concern:

zen of the United States, residing at Duncannon, in the county of Perry, State of Pennsylvania; have invented certain new and useful Improvements ,in Coal-Dust Feeders; andl do hereby declare the-following to be afull,'clear-, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to improvements in that class of'feeders designed to feed powdered fuel to a furnace.

The device is intended, primarily, for use with an ore melting furnace wherein a mixture of air and dust are blasted into the com bustion chamber. "It has been found .in

practice that the usual coal dust feeders do not produce the required result for the reason that littleor no provision is made for regulating the supply of coal dust to mix with a proper quantityof air.

The present invention therefore has for one of its objects the provision of a feeder provided with a means for regulating the flow of coal dust into the path of the blast so that a desired admixture of coal dust and air maybe delivered to the combustion chamber of'the furnace.

Another object is the provision of a feeder provided with a plurality ofconveyer screws and a feed screw and a screen interposed between the feed and conveyor screws so that the admission of relatively large foreign bodies, which would have a tendency to choke or break the conveyer screws, will be prevented.

x A further object is the provision of a feeder including a'hopper and a door connected with the hopper and so positioned that it may be readily opened and the interior of the feed and conveyer apparatus examined and foreign objects which areisometimes, mixed with the coal removed.

A still further object is the provision of a Ifeed screw provided at one end portion with And a. still further object is the provision of i g a geared connection between the feed and Be it known that I, JOHN W. ZnnL, a citiconveyer screws. whereby the latter Will be i rotated at a greater speed than the former.

5 With these and other objects'in view as will more fully hereinafter appear, the present invention consists in certain novel details of construction and arrangement of parts, hereinafter fully described, illustrated 2 in the accompanying drawings and more I particularly pointed out in the appended claims; it being understood that various changes in the form, proportion, size and minor details of the device may be made 'without departing from the spirit or sacrificing any of the advantages of the invention.

In the accompanying drawings forming part of the specification :Figure 1 is a plan view of the device and showing the feed regulating slide open. Fig. 2 is a view showing the conveyer tubes and chute in front throughout.

Thehopper 5 is of the usual flared type and comprises the side walls 5 and 6, and the end walls 7 and 8. The upper and lower edges of these walls are provided with outiployed to designate corresponding parts i i sponds in contour and area to the mouthof the hopper. The lower edges of the side "and end walls of the sleeve are provlded correspondingin width to the width of the flanges 9. and designed to bear upon the latalining openings which receive clamping secured to the hopper. -A portion of the lower face of one of the flanges 11 is cut away'and the flange directly opposite has a portion on its lower face likewise cut away,

with outwardly extending lateral flanges 11,

ter, the said flanges being provided withbolts or nuts by means of which the sleeve is whereby a space is provided which receives elevation and the hopper in vertical section.

wardlv extending lateral flanges 9. A sleeve is designated by the numeral 10, and correa manually erated sliding door 12, which 1 serves, when closed, to prevent the entrance of coal dust into the hopper. Y

What will subsequently be termed a feed 5 screw is designated by the numeral 13. This member is provided at either end with reduced extensions constituting trunnions 14c and 15, the said trunnions being journaled in openings formed in the medial portions and adjacent the upper ends of the end walls 7 and 8 of the hopper. The feed screw 13 is of peculiar constnuction inasmuch as the groove which forms the spiral instead of being cut so that its opposite sides will be 11 of equal width on the contrary is so cut that one of its sides slants outwardly and is con siderably widerthan the opposite sides as shown at 16. With this construction it is evident that the groove will be deeper on the face of one thread than on the opposed faces of the next succeeding thread, whereby the pushing or advance of a large cake of dust or lump of coal wil-lbe performed by one face of the spiral. The spiral extends from one end of thescrew to a point adjacent the opposite end where it terminates in f a plurality of spaced breaker teeth 17. The teeth 17 project beyond the plane of the periphery of the spiral and are arranged in staggered relation, the said teeth following the ourve of the spiral to the opposite end of the screw. l g

lVith this construction it is manifest that a relatively large cake of dust or lump of V coal falling on that end of the feeder remote from the teeth will be advanced through'the coo'peration of the spiral and side walls of the hopper to theteeth l7, and since the space betwe'en the extremities of'these teeth 40 and side walls of the hopper Tisless. than the distance between the periphery of the spiral and said side walls, the teeth 17 will crush the cake or lump to the required size to be fed through the blast pipe and into the furnace. I v

The conveying mechanism .which carries the coal dust from the hopper-to? the blast which directs the said 'coal' dust into thfedurnace will now be described. i Secured to the bottom of the hopper is a boxmg comprising upper andlower plates 18 an 19. The upper plate 18 corresponds 1n wldth to the length of the hopper and is preferably formed of a single casting and is bolted to. lateral flanges 20, extending outi the front side of the hopper. That portion wardlyfrom the lower ends of the end and side walls of the hopper. Thelengt-lrof the upper plate 18 is considerably greater than the width'ofthe lower or contracted end of 60 the hopper and when in positionas shown in 1 and 3, that is with its rear end in allnement with the rear end of the hopper, Y the forward end of said plate will extend for a considerable distance in advance ofbores of t of the upper plate lying below the hopper "is open while the outer end'of the portion extending in advance of the front of the hopper is covered as shown at 21 The covered portion 21 is providedon its lower face with a pluralityof concaved depressions 2-2, which extend in the direction of the length of the plate and terminate in an upwardly extending flange 23, at the, free or outer end of the plate. The. lower plate 1 9 is somewhat less in length than the upper plate 18 and is positioned so that its rear end is in alinelnent. with the rear end of the top plate 18 while its forward end terminates at a point adjacent the forward end of the upper plate 18. The plates 18 and 19 are provided on their opposite sides with lateral flanges 24,11aving openings for the reception of clamping bolts by means bf which the plates are united. The lower plate 19 is provided on its inner face with a plurality of spaced concaved depressions, which are parallel with the depressions 22, in the upper plate, these deprecsions forming circular openings and by irtue of the plates bearing one upon the other the sides of -these depressions will likewise bear, whereby the tubes or openings formed by the depressions will be out of comniunica-' tion with each other.

As before stated, the forward end of the lower plate 19 terminates at a point adja cent the forward end of the upper plate 18,

and this terminal of the lower plate is pro;-

vided with :1 depending flange 25, as clearly shown in' Fig. 3. Riveted or otherwise secured to thh flange 25 and depending from the latter is a. plate 26, corresponding in length to the length of the flange 25, and the lower side of which inclines upwardly as shown in Figs. 2 and 4. Depending from the forward end of the to plate 18 is a, plate 27, the lower side 0 which is in a plane with the lower'side of the plate 26,

.and like the latter inclines upwardly from one end; The plates 26 and 27 form the sides of a chute into which the coal dust" falls from the conveyer tubes.

By reference now to Figs. 1 and 3, it will be seentliat the onterface'of'theplate 27 is provided with a plurality ofbushings 28,

having bores which are in axial alinement with the conveyer tubes and it will be furtherobserved that the rear ends of the up per and lower lates are provided on their outer faces witfi semi-cylindrical boxings 29 bearing one'upon the other, and the bearing surfaces of whichare provided with semicircular grooves which cooperate to form circular openings in axial alinement with the e boxings 2S and conveyer tubes.

The conveyer screws are designated by the numeral 30. In the present instance four of these members are employed; it must be understood however, that I am not to be lim-' ited to this specific number'since it will be 45 8 and secured to theouter face of the latter understood, from what will appear, how a greater or less number might be equally as wellemployed without departing from the spirit of the invention. The screws are positioned in the tubes and have their opposite ends journaled in the bushings 28 and boxings29. It. will be further observed that the spiral or thread of each screw extends from a point adjacent the boxing 29 to the 10 forward end of the lower or shorter plate 19 and formed integral or otherwise secured to'the shaft of each screw are bearing collars 31 and'32, which bear on the inner faces of the bushings and boxings and prevent the entrance of dust into the latter. The conveyer screws conform to the construction of the feed screw. before described, and their rear ends or those extending through the boxings 29 have keyed or otherwise secured 20 thereto a plurality of meshing gears 33. As shown in Fig. 1 the rear end of the shaft of one of the screws projects considerably in advance of the shafts of the other screws and in addition to being provided with the gear which meshes with the adjacent gears is also provided with a pulley 3t. The pulley 34: is driven by a belt 35. the latter in turn being driven by a motor (not shown). With the construction thus described it is evident, owing to the gearing connection between the screws, that each pair will turn in opposite directions therefore in order to accomplish the resultof conveying the coal dust after itfalls from the hopper it is evi- 35 dent that the thread or spiral on one screw of each pair will extend opposite to the thread or spiral of its mate.

In order to connect the feed screw 13 with the conveyer screws the following construc- 40 tion is employed :-By reference now to Fig. 2 it will be seen that the trunnion 15 extends through the end plate 8 of the hopper and is provided with a beveled gear 36, and extending in advance of the end plate is a bracket 37 in which is journaled a vertically disposed shaft 38. Keyed to therapper end of the shaft 38 is a beveled gear 39. the teeth of which mesh with the teeth of the beveled gear 36 and keyed to the lower end of the shaft 38 is a beveled gear 40, in a plane with the lower end of the hopper.

or substantially so. Projecting laterally from the rear end portions of the top and bottom plates is a bracket -11, having a transverse opening in which is journaled one end portion of a shaft 42. Keyed to one end of the shaft 42 is a beveled gear 43, the teeth I of which mesh with the beveled gear 40. at the lower end of the shaft 38. The opposite end of the shaft 42 is provided with a crown gear 44, th teeth of which mesh with the crown gear of the adjacent conveyor screw. the opening of the front side wall when the intermediate portions of the latches will bear The gearing between the conveyer and feed screws is so proportioned that the conveyer screws will rotate at a feed screw. 7

By reference now to Figs. 1, 2 and 4, it will be seen "that the opposite ends of the chute formed by the depending plates 26 and 27 are provided with sleeves -15 and 46. the upper of these sleeves receiving one end of a tube (not shown) extending from a fan blower (not shown). The lower sleeve 46 receives one end of a tube (not shown) which connects the chute with the apparatus wherein the coal dust is mixed with the blast of air and delivered to the furnace.

Thus it will be seen with the construction described when coal dust is fed into the hopper 5 and passes the feed screw 13 it will fall into the conveyer pockets and be from thence moved to the chute by the screws 30. It will be seen that the chute is provided with a slide bottom 47. the opposite sides of which enter into inclined grooves formed on the inner faces of the plates 26 and 27 and adjacent the lower edges thereof.

greater speed thah the By providing a sliding bottom for the chute the latter may be removed whenever desired and the forward ends of the screws inspected or cleaned.

In order to prevent the entrance of foreign substances such as pieces of iron or the like into the conveyer pockets a screen 48- is provided. This member comprises a rectangular frame 49, to the opposite ends of which are secured a plurality of metallic strips 50. spaced apart sufliciently far topermit coal dust to pass therebetween but prevent the passage of relatively large objects. The screen is positioned between the feed screw and conveyer screws and is located directly above the outlet end of the hopper and is supported by a plurality of spaced lugs 51.

secured to the inner faces of the side and end walls of the hopper.

In order that the matter caught by th M screen may be removed therefrom without the necessity of placing the hand into the mouth of the-hopper an opening is formed in the front side wall 6 of the hopper. the lower side of this opening extending to a point-in a plane with the screen. Hingedly secured to the upper side of the opening is.

a door 52, of a size to nicely seal the opening in the front side wall 6. The lower corners of the door 52 are provided with lateral keepers 53. and projecting forwardly from the end walls 7 and 8 are a pair of resilient latches 54. The latches 54 are in a plane with the keepers 53 and their free end portions are bent laterally so that when the door is moved to closed position thekeepers 53 will bear on the inclined ends of the latches 54 and move the same farther outward until the door is completely seated inedges of the side and.end walls of the hopper is removed to provide a space and slidingly fitted in this space is a slide 55, located between the screen and conveyer tubes. The slide 55 "is preferably formed of a single piece of sheet metal and when in closed position as shown in Fig. 2,its outer end will extend a trifle in advance of the end wall 7, of the hopper. Projecting in advance of the end wall 7 of the hopper and secured to the slee'velO, is a bracket arm 56, the free end of which is provided with a depending rack 57 The rack- 54' conforms ap- -proximately to the shape of a sector and its convexed edge is provided with .a plurality of teeth 58. Fulcruined at the outer 'end of the bracket 56 is one end of a lever 59. the lower or free end of which is ldosely fitted in an opening formed in the projecting end of the slide 55. The lever 59 is provided,

-at apoint adjacent the teeth of the rack 57.

with a sleeve 60, in which is; slidingly fitted a bolt 61, adapted to engage with the spaces between the. teeth 58. The bolt 60 is spring pressed and normally held in one of the I spaces between the teeth. An operating lever for the bolt is shown at 62, and is pivoted to the lever 59, and has one end connected with the bolt 61, by means of alink 63. 7

It is manifest that the function of the lever is to move the'slide 55 to a positionto cut off communication between the hopper and conveyer tubes as shown in Fig. 1 and to move the said slide outwardly as shown in Fig. 4. whereby communication is established betweenthe hopper and as many of the conveyer tubes as desired. It has been found in practice that the best results are obtained when the amount of coal 'dust entering the furnace can be regulated with out inany way reducing the power which drives the feeder. Thus it can be seen when the'character of the fuel which is being used demands that a comparatively small amount shall enter the furnace, this amount scale is provided on the outer face of the can be regulated by moving the lever 59 outwardly from the position shown in Fig.

until one or more of the tubes are placed in communication with the hopper.

For convenience in determining the number of tubes in communication with the hopper a rack. Ihis scale will indicate the whole or fractional part of the opening exposed for the admission of coal dust from thehopper into the conveyer tubes since it can be readily seen when the parts are .in position as shown in Fig. 2 that bv moving the lever outwardly to the middle' of. the rack the said lever will aline with the marking one half esaeeo From the foregoing it can be seen that I have provided a device which is exceedingly simple in structure and comparatively inexpensive to manufacture, embodying few parts and these so arranged thatthe danger of derangement will be reduced to a minimum.

What is claimed as new, -1s:-

1. A cold dust feeder comprising a hopper having ascreen in its lower portion, a feed element mounted for rotation in its upper portion and having a spiral feed flange a boxing having one end below the hopper. said boxing being provided with a plurality of passages each of WlliCllCOlllIUllIllCfitGS at one end with the throat of the hopper, conportion, and having a spiral feed. flange, a

boxing having one end below the hopper,

said boxing being provided with a plurality of passages each of which communicates at one end with the throat of the hopper, conveyer screws mounted for rotation in said veyer screws mounted for rotation in said passages. an inclined chute into which the rear ends of the conveyor pas ages discharge, and means to establish and out OK communication between the hopper and conveyer passages. 3. A coal dust having a screen in its lower portion, a feed element mounted for rotation in its upper portion, and having a spiral feed flange, a boxing having one end below the hopper, said boxing being provided with a plurality of passages each of which communicates at one end with the throat of the hopper, con veyer screws mounted for rotation in said passages, and an inclined chute into which .J feeder comprising a hopper the rear ends of the conveyer passages dis-.

of passages eachofwhich communicates at passages, an inclined chute into Which the rear ends of the conveyer passages discharge, said chute being provided in its lower s de at a point below the discharge ends of said conveyer passages, with an opening affording access to the said conveyer screws, and a closure for the said openings. 1

5. In a coal dust feeder,- a' hopper having a sleeve at its upper-end, a slide to cut 0% or establish communication between said sleeve and hopper, a screen in the lower portion of the hopper, a feed element mounted for rotation in the upper portionof the hop-' per and having a spiral feed flange, a boxing having one end below thehopper, said boxing being provided with a plurality of passages, each of which communicates at one end on its upper side with the throat of the hopper, conveyer screws mounted for rotation in said passages, a slide in the throat of the,

i hopper below the said screen, to establish or out off communication between the hopper and the said passages, and a chute into which said passages discharge.

In testimony whereof, I affix my signa--, ture, in presence of two Witnesses.

JOHN W. ZELL. Witnesses F. E. WAsE,

FRANK PENNELL. 

